DUP are wedded to their belief in a stable marriage
Since the passage of the Same-Sex Marriage Act, Tory MPs who are devout Christians have been disheartened. David Cameron's desire to remake his party as modern and inclusive has left them feeling restless.
But the Prime Minister's commitment to recognising the marriage in the tax system is one thing they can all agree on.
On Tuesday Sir Gerald Howarth, who ranted about "aggressive homosexuals" during the gay marriage debate, secured a debate on strengthening family relationships.
Four DUP MPs turned up to show their support for the evangelical wing of the Tory party and to express their views on the importance of family.
The gist of the debate was this: married people are better at raising children and have better health outcomes. Family breakdown costs £46bn a year.
Therefore the state should enco urage marriage and discourage co-habitation. Mothers should be also be encouraged to stay at home and look after the children.
Jim Shannon (above) said 9% of married parents split before their child's fifth birthday compared with 35% of unmarried parents. Children from broken homes are nine times more likely to become young offenders.
Andrew Turner, MP for the Isle of Wight, asked Mr Shannon if there is "a relationship between membership of the IRA and the extremist Protestant organisations and the breakdown of families".
For once, the member for Strangford seemed at a loss for words.
"I cannot give the statistics, but I am sure that there has been some impact," he replied. Sir Gerald reminded us that for the majority of Conservative MPs, marriage "can only be between a man and a woman and remains the core of a stable family".
Tory MPs that contributed to the debate relied on statistics rather than religion in defence of marriage.
William McCrea displayed no squeamishness in expressing his views on that holy state.
"God says, in his precious word, that he put us together in families," he said.
"Although many people have sought to undermine marriage, the scriptural bond of marriage is still the foundation stone of a strong society, and will be in years to come."
Jim Shannon guiltily confessed that his wife had done most of the child-rearing. "I have been married for 26 years and I have a very understanding wife," he said.
"Being a housewife is sometimes a harder job than working in a shop or elsewhere. The way my three boys have come on is a credit to my wife and the guidance she gave them, and I make no bones about that."
Labour MPs ignored the debate.
Their collective view that all relationships should be supported, gay or straight, married or cohabiting, was expressed by shadow minister Steve McCabe.
"I do not feel that my divorce has prevented me from being able to have a further solid relationship; nor has it prevented me from having a strong parental role or from being part of a family," he said.
The DUP's message was loud and clear – marriage is the best for everyone, except gay and lesbian people.